summaryrefslogtreecommitdiff
path: root/gdb/sparc64obsd-tdep.c
blob: 55f0d4982efb3913c564b96078e3e30e8e218b3b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
/* Target-dependent code for OpenBSD/sparc64.

   Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "frame.h"
#include "frame-unwind.h"
#include "gdbcore.h"
#include "osabi.h"
#include "regcache.h"
#include "regset.h"
#include "symtab.h"
#include "objfiles.h"
#include "trad-frame.h"

#include "gdb_assert.h"

#include "obsd-tdep.h"
#include "sparc64-tdep.h"
#include "solib-svr4.h"
#include "bsd-uthread.h"

/* OpenBSD uses the traditional NetBSD core file format, even for
   ports that use ELF.  The core files don't use multiple register
   sets.  Instead, the general-purpose and floating-point registers
   are lumped together in a single section.  Unlike on NetBSD, OpenBSD
   uses a different layout for its general-purpose registers than the
   layout used for ptrace(2).  */

/* From <machine/reg.h>.  */
const struct sparc_gregset sparc64obsd_core_gregset =
{
  0 * 8,			/* "tstate" */
  1 * 8,			/* %pc */
  2 * 8,			/* %npc */
  3 * 8,			/* %y */
  -1,				/* %fprs */
  -1,
  7 * 8,			/* %g1 */
  22 * 8,			/* %l0 */
  4				/* sizeof (%y) */
};

static void
sparc64obsd_supply_gregset (const struct regset *regset,
			    struct regcache *regcache,
			    int regnum, const void *gregs, size_t len)
{
  const char *regs = gregs;

  sparc64_supply_gregset (&sparc64obsd_core_gregset, regcache, regnum, regs);
  sparc64_supply_fpregset (regcache, regnum, regs + 288);
}


/* Signal trampolines.  */

/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
   in virtual memory.  The randomness makes it somewhat tricky to
   detect it, but fortunately we can rely on the fact that the start
   of the sigtramp routine is page-aligned.  We recognize the
   trampoline by looking for the code that invokes the sigreturn
   system call.  The offset where we can find that code varies from
   release to release.

   By the way, the mapping mentioned above is read-only, so you cannot
   place a breakpoint in the signal trampoline.  */

/* Default page size.  */
static const int sparc64obsd_page_size = 8192;

/* Offset for sigreturn(2).  */
static const int sparc64obsd_sigreturn_offset[] = {
  0xf0,				/* OpenBSD 3.8 */
  0xec,				/* OpenBSD 3.6 */
  0xe8,				/* OpenBSD 3.2 */
  -1
};

static int
sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
{
  CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1));
  unsigned long insn;
  const int *offset;

  if (name)
    return 0;

  for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++)
    {
      /* Check for "restore %g0, SYS_sigreturn, %g1".  */
      insn = sparc_fetch_instruction (start_pc + *offset);
      if (insn != 0x83e82067)
	continue;

      /* Check for "t ST_SYSCALL".  */
      insn = sparc_fetch_instruction (start_pc + *offset + 8);
      if (insn != 0x91d02000)
	continue;

      return 1;
    }

  return 0;
}

static struct sparc_frame_cache *
sparc64obsd_frame_cache (struct frame_info *next_frame, void **this_cache)
{
  struct sparc_frame_cache *cache;
  CORE_ADDR addr;

  if (*this_cache)
    return *this_cache;

  cache = sparc_frame_cache (next_frame, this_cache);
  gdb_assert (cache == *this_cache);

  /* If we couldn't find the frame's function, we're probably dealing
     with an on-stack signal trampoline.  */
  if (cache->pc == 0)
    {
      cache->pc = frame_pc_unwind (next_frame);
      cache->pc &= ~(sparc64obsd_page_size - 1);

      /* Since we couldn't find the frame's function, the cache was
         initialized under the assumption that we're frameless.  */
      cache->frameless_p = 0;
      addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
      if (addr & 1)
	addr += BIAS;
      cache->base = addr;
    }

  /* We find the appropriate instance of `struct sigcontext' at a
     fixed offset in the signal frame.  */
  addr = cache->base + 128 + 16;
  cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, next_frame);

  return cache;
}

static void
sparc64obsd_frame_this_id (struct frame_info *next_frame, void **this_cache,
			   struct frame_id *this_id)
{
  struct sparc_frame_cache *cache =
    sparc64obsd_frame_cache (next_frame, this_cache);

  (*this_id) = frame_id_build (cache->base, cache->pc);
}

static void
sparc64obsd_frame_prev_register (struct frame_info *next_frame,
				 void **this_cache,
				 int regnum, int *optimizedp,
				 enum lval_type *lvalp, CORE_ADDR *addrp,
				 int *realnump, gdb_byte *valuep)
{
  struct sparc_frame_cache *cache =
    sparc64obsd_frame_cache (next_frame, this_cache);

  trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
				optimizedp, lvalp, addrp, realnump, valuep);
}

static const struct frame_unwind sparc64obsd_frame_unwind =
{
  SIGTRAMP_FRAME,
  sparc64obsd_frame_this_id,
  sparc64obsd_frame_prev_register
};

static const struct frame_unwind *
sparc64obsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
{
  CORE_ADDR pc = frame_pc_unwind (next_frame);
  char *name;

  find_pc_partial_function (pc, &name, NULL, NULL);
  if (sparc64obsd_pc_in_sigtramp (pc, name))
    return &sparc64obsd_frame_unwind;

  return NULL;
}

/* Kernel debugging support.  */

static struct sparc_frame_cache *
sparc64obsd_trapframe_cache (struct frame_info *next_frame, void **this_cache)
{
  struct sparc_frame_cache *cache;
  CORE_ADDR sp, trapframe_addr;
  int regnum;

  if (*this_cache)
    return *this_cache;

  cache = sparc_frame_cache (next_frame, this_cache);
  gdb_assert (cache == *this_cache);

  sp = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
  trapframe_addr = sp + BIAS + 176;

  cache->saved_regs = trad_frame_alloc_saved_regs (next_frame);

  cache->saved_regs[SPARC64_STATE_REGNUM].addr = trapframe_addr;
  cache->saved_regs[SPARC64_PC_REGNUM].addr = trapframe_addr + 8;
  cache->saved_regs[SPARC64_NPC_REGNUM].addr = trapframe_addr + 16;

  for (regnum = SPARC_G0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
    cache->saved_regs[regnum].addr =
      trapframe_addr + 48 + (regnum - SPARC_G0_REGNUM) * 8;

  return cache;
}

static void
sparc64obsd_trapframe_this_id (struct frame_info *next_frame,
			       void **this_cache, struct frame_id *this_id)
{
  struct sparc_frame_cache *cache =
    sparc64obsd_trapframe_cache (next_frame, this_cache);

  (*this_id) = frame_id_build (cache->base, cache->pc);
}

static void
sparc64obsd_trapframe_prev_register (struct frame_info *next_frame,
				     void **this_cache,
				     int regnum, int *optimizedp,
				     enum lval_type *lvalp, CORE_ADDR *addrp,
				     int *realnump, gdb_byte *valuep)
{
  struct sparc_frame_cache *cache =
    sparc64obsd_trapframe_cache (next_frame, this_cache);

  trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
				optimizedp, lvalp, addrp, realnump, valuep);
}

static const struct frame_unwind sparc64obsd_trapframe_unwind =
{
  NORMAL_FRAME,
  sparc64obsd_trapframe_this_id,
  sparc64obsd_trapframe_prev_register
};

static const struct frame_unwind *
sparc64obsd_trapframe_sniffer (struct frame_info *next_frame)
{
  CORE_ADDR pc;
  ULONGEST pstate;
  char *name;

  /* Check whether we are in privileged mode, and bail out if we're not.  */
  pstate = frame_unwind_register_unsigned (next_frame, SPARC64_PSTATE_REGNUM);
  if ((pstate & SPARC64_PSTATE_PRIV) == 0)
    return NULL;

  pc = frame_unwind_address_in_block (next_frame, NORMAL_FRAME);
  find_pc_partial_function (pc, &name, NULL, NULL);
  if (name && strcmp (name, "Lslowtrap_reenter") == 0)
    return &sparc64obsd_trapframe_unwind;

  return NULL;
}


/* Threads support.  */

/* Offset wthin the thread structure where we can find %fp and %i7.  */
#define SPARC64OBSD_UTHREAD_FP_OFFSET	232
#define SPARC64OBSD_UTHREAD_PC_OFFSET	240

static void
sparc64obsd_supply_uthread (struct regcache *regcache,
			    int regnum, CORE_ADDR addr)
{
  CORE_ADDR fp, fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET;
  gdb_byte buf[8];

  gdb_assert (regnum >= -1);

  fp = read_memory_unsigned_integer (fp_addr, 8);
  if (regnum == SPARC_SP_REGNUM || regnum == -1)
    {
      store_unsigned_integer (buf, 8, fp);
      regcache_raw_supply (regcache, SPARC_SP_REGNUM, buf);

      if (regnum == SPARC_SP_REGNUM)
	return;
    }

  if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM
      || regnum == -1)
    {
      CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET;

      i7 = read_memory_unsigned_integer (i7_addr, 8);
      if (regnum == SPARC64_PC_REGNUM || regnum == -1)
	{
	  store_unsigned_integer (buf, 8, i7 + 8);
	  regcache_raw_supply (regcache, SPARC64_PC_REGNUM, buf);
	}
      if (regnum == SPARC64_NPC_REGNUM || regnum == -1)
	{
	  store_unsigned_integer (buf, 8, i7 + 12);
	  regcache_raw_supply (regcache, SPARC64_NPC_REGNUM, buf);
	}

      if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM)
	return;
    }

  sparc_supply_rwindow (regcache, fp, regnum);
}

static void
sparc64obsd_collect_uthread(const struct regcache *regcache,
			    int regnum, CORE_ADDR addr)
{
  CORE_ADDR sp;
  gdb_byte buf[8];

  gdb_assert (regnum >= -1);

  if (regnum == SPARC_SP_REGNUM || regnum == -1)
    {
      CORE_ADDR fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET;

      regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf);
      write_memory (fp_addr,buf, 8);
    }

  if (regnum == SPARC64_PC_REGNUM || regnum == -1)
    {
      CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET;

      regcache_raw_collect (regcache, SPARC64_PC_REGNUM, buf);
      i7 = extract_unsigned_integer (buf, 8) - 8;
      write_memory_unsigned_integer (i7_addr, 8, i7);

      if (regnum == SPARC64_PC_REGNUM)
	return;
    }

  regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf);
  sp = extract_unsigned_integer (buf, 8);
  sparc_collect_rwindow (regcache, sp, regnum);
}


static void
sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  tdep->gregset = regset_alloc (gdbarch, sparc64obsd_supply_gregset, NULL);
  tdep->sizeof_gregset = 832;

  /* Make sure we can single-step "new" syscalls.  */
  tdep->step_trap = sparcnbsd_step_trap;

  frame_unwind_append_sniffer (gdbarch, sparc64obsd_sigtramp_frame_sniffer);
  frame_unwind_append_sniffer (gdbarch, sparc64obsd_trapframe_sniffer);

  sparc64_init_abi (info, gdbarch);

  /* OpenBSD/sparc64 has SVR4-style shared libraries.  */
  set_solib_svr4_fetch_link_map_offsets
    (gdbarch, svr4_lp64_fetch_link_map_offsets);
  set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver);

  /* OpenBSD provides a user-level threads implementation.  */
  bsd_uthread_set_supply_uthread (gdbarch, sparc64obsd_supply_uthread);
  bsd_uthread_set_collect_uthread (gdbarch, sparc64obsd_collect_uthread);
}


/* Provide a prototype to silence -Wmissing-prototypes.  */
void _initialize_sparc64obsd_tdep (void);

void
_initialize_sparc64obsd_tdep (void)
{
  gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
			  GDB_OSABI_OPENBSD_ELF, sparc64obsd_init_abi);
}